AFTER VACILLATING for seven months, Republicans have apparently settled on a strategy to exploit President Clinton's infidelity.

The Grand Old Party, once known for its tough stances on crime and taxes, is now casting itself as a guardian of honesty and integrity. On matters ranging from the budget, the 2000 census and who to vote for in November, Americans can expect Republicans to repeat a familiar reprise: We are the ones who can be trusted.

The first sign of the new aggressive posture came on the Senate's first day back from its August recess, as Majority Leader Trent Lott, R-Miss., met with reporters to outline the month's busy schedule. After the predictable moralizing on Clinton's behavior, Lott said:

"I noted last year that the president and the Congress entered into a historic budget agreement. Now the president threatens to shut down the government because we will not give him more money than he agreed to with us, to spend last year. I don't believe the American people will stand for that. We had his word on the budget before the entire nation. Now we're going to see how much his word is really worth."

In a few sentences, Lott superimposed the president's personal failures onto the Democrat Party's budget policies. Past budget battles have been fought over fiscal responsibility, tax equity, spending priorities and pork. But in this, the Lewinsky era of American politics, it is about honesty.

A similar theme was raised by party strategists who unveiled a $37 million ad campaign directed at expanding their narrow majority in the House. The first ad, for a GOP candidate from Las Vegas, concludes: "Honesty does matter."

"We see that integrity and honesty in government have risen to the top of the charts in terms of the interest of the public," said Repre sentative John Linder, the Geogria Republican who heads up the effort to elect Republicans to the House. "It used to be taxes and crime issues. It is now honesty and integrity in government."

Republicans are embracing the integrity issue from coast to coast. Last week, California Attorney General Dan Lungren released the first commercial in his campaign for governor.

"Character is doing right when no one is looking," Lungren says in the ad.

For months, the president's high approval ratings had confounded critics, such as House Speaker Newt Gingrich, R-Ga., who declared in the spring that he would mention Clinton's "crimes" in every speech, only to stop talking about it for the summer.

But everything changed after Clinton's August 17 sort of-confession. Politicians who had previously said no one outside Washington cared, returned from their districts telling a different story. Republicans now insist they now have polls that show the issue works in their favor. Already, two GOP House candidates have begun running ads that directly attack the president's integrity.

The Republican Party -- home to Bob Packwood, Ollie North and Richard Nixon -- does not pretend to have a monopoly on virtue. But if harping on the Democratic president's ethical lapses helps them advance their cause, they are now ready to do so.